Device with controllable pitch propeller for outboard motors

ABSTRACT

A device with a variable pitch propeller for an outboard motor that allows for controllable pitch and can be mounted to a standard outboard motor without significant modifications. The device includes a variable pitch propeller having a front side and a rear side. The variable pitch propeller can be mounted to a shaft of the outboard motor at the front side thereof. A pitch control assembly is coupled to the rear side of the variable pitch propeller for controlling the pitch of the variable pitch propeller. The pitch control assembly includes a servo linear actuator. The pitch control assembly is further mounted to the outboard motor through a mounting member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from a U.S. Provisional Patent App. No. 63/318,501 filed on Mar. 10, 2022, which is incorporated herein by reference in its entirety.

FIELD OF INVENTION

The present invention relates to a device for an outboard motor, and more particularly, the present invention relates to a device with a controllable pitch propeller for outboard motors.

BACKGROUND

Existing Outboard Motors are generally based on a constant pitch propeller. The constant pitch propellers have their pitch fixed and remains fixed throughout their operation from 0 RPM to Max RPM. Constant pitch propellers are designed to work efficiently at a set RPM and this efficiency drops significantly at another RPM due to the fixed pitch. Also, the efficiency drops when the vessel moves. The torque output curve is typically non-linear when plotted against RPM and power output. The propeller torque requirement on the other hand is close to linear. So, constant pitch propellers generally have a mismatch of the output torque and the torque required by the propeller. This means at some instances, more torque is available than the propeller needs and in other instances, particularly at high RPM, less torque is available than what the propeller needs at that RPM, so the output engine has to compensate for that using more throttle input and more fuel.

Many attempts have been made in the art for incorporating a variable pitch propeller on an outboard motor. However, such attempts have failed because modifying the lower end of the outboard to house the pitch control mechanism is almost impossible due to size constraints and an increase in drag. The attempts have failed to put the pitch control mechanism in a small space of the hub of the propeller.

A need is therefore appreciated for an improved design of a variable pitch controller that is devoid of the above drawbacks of the fixed pitch controller.

SUMMARY OF THE INVENTION

The following presents a simplified summary of one or more embodiments of the present invention to provide a basic understanding of such embodiments. This summary is not an extensive overview of all contemplated embodiments and is intended to neither identify critical elements of all embodiments nor delineate the scope of any or all embodiments. Its sole purpose is to present some concepts of one or more embodiments in a simplified form as a prelude to the more detailed description that is presented later.

The principal object of the present invention is therefore directed to a controllable pitch propeller for outboard motors.

It is another object of the present invention that the propeller pitch is adjustable over a wide range of 0 to +90 degrees and 0 to −90 degrees.

It is still another object of the present invention that the propeller can provide forward thrust or backward thrust depending on the user setting of the pitch without changing outboard gear from forward to reverse.

It is a further object of the present invention that the pitch control mechanism can be installed in the hub of the propeller without any significant increase in the diameter or length of the hub.

It is a further object of the present invention that the propeller hub can be of a standard diameter.

It is still a further object of the present invention that the device can provide reverse thrust when required without changing gear or slowing down.

It is yet a further object of the present invention that the propeller provides more thrust at a given Engine RPM.

In one aspect, disclosed is an outboard motor with a controllable pitch propeller. The Device includes a novel mechanism for mounting a controllable pitch propeller. The pitch control mechanism can be installed in the hub of the propeller without any significant increase in the diameter or length of the hub.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying figures, which are incorporated herein, form part of the specification and illustrate embodiments of the present invention. Together with the description, the figures further explain the principles of the present invention and to enable a person skilled in the relevant arts to make and use the invention.

FIG. 1 is a left side view of an outboard motor with the device, according to an exemplary embodiment of the present invention.

FIG. 2 is a bottom view of the outboard motor shown in FIG. 1 , according to an exemplary embodiment of the present invention.

FIG. 3 is an enlarged view of the bottom of the outboard motor shown in FIG. 1 , more clearly showing the device, according to an exemplary embodiment of the present invention.

FIG. 4 is a perspective view of the device, according to an exemplary embodiment of the present invention.

FIG. 5 is an exploded view of the device, according to an exemplary embodiment of the present invention.

FIG. 6 shows an embodiment of a propeller blade having a hydrofoil and circular root, according to an exemplary embodiment of the present invention.

FIG. 7 shows a propeller hub, according to an exemplary embodiment of the present invention.

FIG. 8A shows a perspective view of a propeller base, according to an exemplary embodiment of the present invention.

FIG. 8B shows another perspective view of the propeller base, according to an exemplary embodiment of the present invention.

FIG. 9 shows the propeller bases mounted into holes of the propeller hub and the propeller blades coupled to the propeller bases, according to an exemplary embodiment of the present invention.

FIG. 10A is a perspective view of a plunger, according to an exemplary embodiment of the present invention.

FIG. 10B is another perspective view of the plunger, according to an exemplary embodiment of the present invention.

FIG. 11 shows a locking plate, according to an exemplary embodiment of the present invention.

FIG. 12A shows a spline core, according to an exemplary embodiment of the present invention.

FIG. 12B shows another perspective view of the spline core, according to an exemplary embodiment of the present invention.

FIG. 13A shows a plunger bearing mount, according to an exemplary embodiment of the present invention.

FIG. 13B shows another perspective view of the plunger bearing mount, according to an exemplary embodiment of the present invention.

FIG. 14 shows a partial exploded view having a precision electromechanical actuator, an acme screw, a push pull shaft, the plunger bearing mount, and the plunger, according to an exemplary embodiment of the present invention.

FIG. 15 shows the actuator seal housing and the push pull shaft, according to an exemplary embodiment of the present invention.

FIG. 16 is a partial exploded view of major components of the device, according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

Subject matter will now be described more fully hereinafter. Subject matter may, however, be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any exemplary embodiments set forth herein; exemplary embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, for example, the subject matter may be embodied as apparatus and methods of use thereof. The following detailed description is, therefore, not intended to be taken in a limiting sense.

The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term “embodiments of the present invention” does not require that all embodiments of the invention include the discussed feature, advantage, or mode of operation.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting to embodiments of the invention. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The following detailed description includes the best currently contemplated mode or modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense but is made merely to illustrate the general principles of the invention since the scope of the invention will be best defined by the allowed claims of any resulting patent.

The following detailed description is described with reference to the drawings, wherein reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, specific details may be set forth in order to provide a thorough understanding of the subject innovation. It may be evident, however, that the claimed subject matter may be practiced without these specific details. In other instances, well-known structures and apparatus are shown in block diagram form to facilitate describing the subject innovation. Moreover, the drawings may not be to scale.

REFERENCE NUMERALS

-   -   102 Mounting member     -   103 Actuator     -   104 Actuator main frame     -   106 Geared servo motor     -   108 Actuator plunger shaft     -   110 Actuator bearing frame     -   112 Actuator bearing lock     -   114 Actuator seal housing     -   116 Push pull shaft     -   118 Plunger bearing mount     -   120 Blades     -   122 Bearing     -   124 Plunger bearing lock plate     -   126 Plunger     -   128 Propeller base     -   130 Plunger lock plate     -   132 Spline hub     -   134 Variable pitch propeller hub

Disclosed is a device with a variable pitch propeller for an outboard motor. In one implementation, the disclosed device includes a variable pitch propeller, a pitch control mechanism, and a mounting member. Also, disclosed is an outboard motor with the disclosed controllable pitch propeller. The pitch control mechanism can be installed in the hub of the propeller without significantly changing the dimensions of the hub, which is the chief advantage of the disclosed invention. The disclosed pitch control mechanism and the propeller hub can be installed in standard outboard motors without significant modifications, making the disclosed invention versatile.

Referring to FIG. 1 which shows the disclosed device 100 mounted to an outboard motor 10. FIG. 2 shows the bottom view of the outboard motor 10. FIG. 3 shows an enlarged view of a bottom of the outboard motor 10 clearly showing the device 100 mounted to a body of the outboard motor. FIG. 4 shows a perspective view of disclosed device 100 and FIG. 5 shows an exploded view thereof. As shown in FIGS. 3 and 4 , the device 100 includes an actuator 103 and a mounting member 102. The actuator can be encased within an actuator frame 104. The mounting member 102 is coupled to the actuator frame 104, and the mounting member is used to mount the disclosed device to the top fin hard point of the outboard motor. The actuator is coupled to the rear side of the propeller hub, and thus requiring non-significant modifications in standard outboard motors. The structure and dimensions of the mounting member can be varied without departing from the scope of the present invention. Moreover, suitable damping mechanisms can also be used to reduce vibrations between the outboard motor and the disclosed device.

The device 100 can include a servo-based linear actuator assembly, one or more variable pitch propellers, and a digital propeller pitch controller. FIG. 1 shows the servo-based linear actuator assembly mounted to a top fin hard point of outboard motor 200.

The controller, in one implementation, can be a microcontroller, such as an Atmega328 microcontroller. The controller can monitor the one or more parameters of the vessel, such as engine RPM and speed and can compute the optimum pitch for the propeller for better efficiency, higher thrust, and acceleration. The Engine torque vs RPM values can be stored, for example, on the ATmega EPROM. The controller can be operably connected to the servo liner actuator.

Referring to FIG. 4 , the actuator assembly can include an actuator frame 120, a servo motor 134 is encased within a servo mount 132, and the servo mount can be encased with actuator frame 120. The servo motor 134 can drive an acme screw 136, also encased within the actuator frame 120. Angular contact bearings 128 and a bearing mount 130 can be used to couple the servo motor 134 to the ball nut 126. The polyurethane seals 124 and the water seal mounts can be used to stop water from getting into the actuator internals. In one implementation, silicon seals encased within the seal housing can allow for the linear motion of a push-pull shaft while preventing any ingress of water that may damage the internal components. The servo motor that can be high precision motor, such as having a micrometer accuracy. In one case, the actuator can move the push-pull rod linearly with accuracy up to 0.1 mm.

In operation, the servo motor can rotate the acme screw and the rotary motion of the acme screw is converted to linear motion of the nut. The nut is connected to a push-pull rod. The push-pull rod can be connected to the propeller through a shaft 138. A control rod stabilizer 114 can extend from the actuator frame and can stabilize the shaft of the push-pull rod. The shaft can be connected to the plunger of the propeller. Moving the plunger in and out of the propeller hub can adjust the propeller pitch.

The variable pitch propeller can include a hub shell 108, the plunger 140, a spline core 112, and blades 107. The hub shell is cylindrical stainless-steel housing inside which the plunger and spline core are housed. The blades extend radially outwards from the outer surface of the hub shell, wherein the hub shell has holes for plunger base to which can be installed the blades. The plunger can slide within the propeller hub for modifying the orientation of the blades i.e., the pitch. The plunger can have grooves for the blade's lower end. As the plunger slides in or out of the hub shell, the pitch of the blade changes. The whole mechanism can be referred to as a slider crank mechanism, wherein the sliding motion of the plunger can be converted to the rotary motion of the blades.

The variable pitch propeller can be connected to an outboard output shaft. The spline core has splines to mesh with the outboard output shaft and provide a torque transfer mechanism from the shaft to the propeller.

The propeller blade has two main parts i.e., a hydrofoil and a circular root. FIG. 6 shows an embodiment of the propeller blade 600 having hydrofoil 610 and the circular root 620. Propeller blades can be made of stainless steel, bronze, or similar material known to a skilled person for use in making the propeller blades. The circular root 620 mounts into a propeller hub shown in FIG. 8A. The circular root 620 has a threaded locking bolt hole 640 and a locking key groove 630. A locking key secures the propeller blade 600 to the propeller base 700 and prevents the propeller blade from rotating in the propeller base. The locking bolt on the other hand can lock the propeller blade inside the propeller base and prevents it from detaching due to centrifugal forces during rotation.

The drawings show the variable pitch propeller having four blades; however, the number of blades can vary without departing from the scope of the present invention. Function of the propeller blade is known i.e., to provide thrust force when spun around its axis. The profile of the blade can vary and any shape and size of the blade including diameter of the propeller is within the scope of the present invention.

The variable pitch propeller further includes a propeller hub, also referred to herein as hub shell. FIG. 7 shows an embodiment of the propeller hub 700 that may be cylindrical and housing different parts of the variable pitch propeller. The propeller hub can be made from stainless less or similar material known for use in making propellers. The propeller hub 700 has holes 710 for mounting the propeller blades. These holes can receive the propeller base and the circular root of the propeller blade can be mounted to the propeller base. The number of holes 710 therefore can correspond to the number of propeller blades. However, the number of holes 710 can vary independent of the propeller blades without departing from the scope of the present invention. Other holes 720 can be for securing other components.

The variable pitch propeller further includes propeller bases mounted to the propeller hub. The propeller blades are installed into the propeller bases. The number of propeller blades corresponds to the number of propeller blades. Thus, four propeller bases can be provided for four propeller blades. FIGS. 8A and 8B show different perspective views of a propeller base 800. On top side, the propeller base can have a groove 810 into which the circular root of the propeller blade can be received. The groove 810 has a locking key holes 820 for the locking key and two locking bolts holes 820 for the locking bolt.

On the bottom side of the propeller base can be a Cam follower 840. The propeller base can convert the linear motion of the servo linear actuator assembly into a rotary motion of the propeller blade resulting in change in the pitch. The propeller base can be made of high strength stainless steel alloy or similar material. The propeller blades can be mounted to the propeller base, wherein the locking key secures the propeller blade to the propeller base and prevents the blade from rotating relative to the propeller base. The locking bolt passing through the circular root can stop the propeller from separating. The propeller base can fit inside the propeller hub and together they can rotate around an axis of the propeller base, also referred to herein as axis of rotation. FIG. 9 shows the propeller bases 800 mounted into holes of the propeller hub 700 and the propeller blades coupled to the propeller bases. One of the blades is removed for showing the propeller base.

The disclosed device further includes a plunger, FIGS. 10A and 10B shows different perspective views of the plunger 1000. The plunger can fit inside the propeller hub and moves linearly along the axis of rotation of the propeller. The plunger can be made from aluminum or similar material. The plunger has elongated slots 1010 that mesh with the Cam follower 840 of the propeller bases for the cam crank mechanism. There are four elongated slots for the four propeller bases. As the plunger moves linearly, the linear motion of the plunger is converted to rotary motion of the propeller base by the cam crank mechanism. This in turn causes the blade pitch to change depending on how far the plunger moves linearly. Thus, the displacement of the plunger is proportional to the change in pitch of the propeller blades. The plunger further has two plunger lock plates that locks the CAM mechanism of the propeller base in its place. FIGS. 10A and 10B further show the holes 1020 for fastening the two plunger plates on each side of the plunger. The pitch of the propeller blades can be adjusted to desired degrees, such as by +/−90 degrees. Also, shown in the drawings are the passages 1030 for the exhaust gasses.

As shown in FIG. 9 , the propeller base can fit inside the propeller hub and can rotate around its axis. When the plunger moves linearly, the propeller base rotates around its axis and rotates the propeller blades. This causes the pitch of the propeller blades to change since the blades are fixed in the propeller base. The translation of the motion can be precise so that accurate pitch of the propeller can be achieved.

The spline Core fits inside the propeller hub and has splines that mesh with splines on the outboard propeller shaft during installation. The purpose of the spline Core is to allow the propeller to be locked to the outboard propeller shaft and be rotated at low to max rpm. The spline core 112 also has slots 110 for exhaust gases from the outboard engine to vent out at the back of the propeller without interruption and thus create additional thrust. The spline core is fixed to the propeller hub with screws. FIG. 11 illustrates the coupling of the propeller bases 800 to the plunger 1000. One of the propeller bases is shown separated to illustrate the mechanism. The cam follower 840 can be seen mounted inside the elongated slot of the plunger. FIG. 11 also shows the locking plate 1040.

FIGS. 12A and 12B show different perspective views of the spline core 1200 that allows the propeller to be coupled to the outboard propeller shaft for rotating the propeller. The spline core 1200 can fit inside the propeller hub and has splines 1210 that mesh with splines on outboard propeller shaft during installation. The spline core also has the passages 1220 for the exhaust gasses. The exhaust gasses from the outboard engine can vent out at the back of the propeller through the spline core and the plunger without any interruption and may also provide an additional thrust to the vessel. The spline core can be fixed to the propeller hub through fasteners, such as screws.

FIGS. 13A and 13B show different perspective view of a plunger bearing mount 1300 that can fit inside the back of propeller hub. The plunger bearing mount can move linearly along the axis of rotation. The plunger bearing mount houses a double row angular contact ball bearing. The push pull shaft fixes in the center of the bearing. As the push pull shaft moves linearly it moves the plunger bearing mount along with it while still allowing the propeller to rotate without interruption. The plunger bearing mount is fixed to the plunger with screws and moves the plunger with it. The plunger itself transforms the linear motion to rotary motion of the propeller base and the propeller base in turn rotates the blades.

FIG. 14 shows a Precision electromechanical actuator 1410, an acme screw 1420, a push pull shaft 1430, the plunger bearing mount 1300, and the plunger 1000. The electromechanical actuator can move the push pull shaft linearly. The electromechanical actuator can be of a high precision, such as having an accuracy of up to 0.1 mm. The actuator includes a servo motor for providing precise angular rotation. The angular rotation of the servo shaft is converted to linear motion of push pull rod. The servo motor may have an accuracy of about 0.1 degrees. It is understood that accuracy may vary and any variation in the accuracy is within the scope of the present invention.

The push pull shaft can essentially be made from aluminum and has a rod shape profile. However, any other material for the push pull rod is within the scope of the present invention. The push pull shaft has female threads at one end that meshes with the male threads on the acme screw. The servo motor rotates the Acme screw in the push pull shaft. Due to the meshing threads, the rotary motion is transformed into linear motion of the push pull shaft. The servo motor may have a high-resolution rotary encoder that can keep precise angular position. FIG. 14 shows the components in order of assembly.

The actuator may further include an actuator seal housing that includes silicone seals that allow for linear motion of the push pull shaft but stops water from getting inside that may damage the servo motor. FIG. 15 shows the actuator seal housing 1500 and the push pull shaft. The actuator seal housing has an elongated groove 1510 and the push pull shaft has an elongated key 1432, wherein the groove and key can slidably interlock preventing rotation of the push pull shaft but allows the linear motion.

Referring to FIG. 16 which shows a partial exploded view having major components of the disclosed device in order of assembly. FIG. 16 shows an actuator frame 1630, a servo motor 1410, actuator bearing mount 1610, actuator bearing lock plate 1620, actuator seal housing 1500, acme screw 1420, push pull shaft 1430, plunger bearing mount 1300, plunger bearing lock plate with seal 1640, plunger 1000, propeller hub 700, and spline core 1200. The actuator may further include actuator bearing mount 1610 for holding an angular contact ball bearing. The actuator can produce over 40 kg of push pull force and the bearing is there to take the reactionary force and not allow the servo being damaged.

The mounting member 102, also referred to herein as a pusher shaft support, may be a Stainless-steel rod or similar structure that is of a hydrodynamic design for low drag and connects the actuator to the outboard using bolts. It is understood that the mounting member can be made from any other material and any variations in the design of mounting member is within the scope of the present invention.

As shown in FIGS. 1-3 , the variable pitch propeller at its front side is coupled to the shaft of the outboard motor and the pitch control assembly of the disclosed device is coupled to the rear side of the variable pitch propeller and the pitch control assembly is further mounted to the body of the outboard motor. The controller can operate and control the functioning of the disclosed device. The controller can be installed in the boat at a safe location that may be waterproof. The controller can be connected to the engine rpm sensor, boat speed sensor, and the outboard gear shifter. The controller can take one or more inputs from one or more sensors of the boat to automatically determine the right pitch for the propeller. The controller can then cause the change in the pitch to the desired pitch by sending a signal to the actuator. The actuator upon receiving the signal, which indicates the precise degree of momentum, can displace the push pull rod. The push pull rod in turn can displace the plunger bearing mount, the plunger bearing mount in turn moves the planter and the plunger can rotate the propeller base at a precise angle while keeping its position locked all the time. The rotation of the propeller base rotates the blades to achieve the desired pitch.

It is to be noted that the controller can compute and adjust the positive pitch of the propeller as well as negative pitch. In case, the user sets the electronic gear shifter to forward, the controller sets the pitch of the propeller to as positive value and hence the boat moves forward. But if the user sets the electronic gear shifter to reverse, the controller sets the pitch of the propeller to a negative value and hence the boat can brake very effectively because of reverse thrust and can also move backwards. This is advantageous that allows for thrust reversal without changing the gear to reverse on the outboard itself. Moreover, the in-built reverse gear mechanism in the outboard motor can be omitted while the disclosed device can cause the boat to move backwards and also brake efficiently.

In certain implementations, the controller can be an 8-bit microcontroller with set of instructions to determine optimum blade angle based on a variety of inputs for better fuel efficiency, acceleration, and thrust reversal/braking. The controller can process instructions in fraction of a second providing between control over the boat. For example, it may take the controller less than 2 ms to compute a solution for optimum blade angle and instruct the servo to change the blade angle and keep the blade angle locked until further instruction. The controller includes suitable processing circuitry and a memory for storing the set of instructions.

In certain implementations, the disclosed device may also include collision avoidance features which may take inputs from different proximity sensors on the hull of the boat placed in strategic locations. In the event of a potential collision, the disclosed controller can set the pitch to zero degree for zero net thrust. It is understood that instead of the proximity sensors, any other detection mechanism can be used without departing from the scope of the present invention.

In certain implementations, the controller may also include a GPS module and an inertial navigation module, both modules work together and allows autonomous navigation of the boat, preprogrammed, acceleration regime for the boat, preprogrammed cruise speed, and auto parking.

In certain implementations, the Actuator Mount can be coupled to the actuator frame at one end and the other end can be coupled to the upper fin area of the outboard using fasteners, such as bolts. A rubber dampener, or similar dampening mechanism, can be inserted between the mount surface matting with the anti-ventilation plate located on the lower unit of the outboard. The rubber dampener allows for a slight play since the actuator and propeller will always have a slight misalignment. This allows the propeller to rotate smoothly and also prevent the actuator mount from breaking due to misalignment's threaded holes are made in the upper fin area of the outboard for the mounting bolts. The bolts can be countersunk Allen bolts and can be flush with actuator mounting surface.

The pusher shaft support can be a stainless-steel rod that is of hydrodynamic design for low drag and connects the actuator to the outboard using bolts.

In operation, the propeller can be installed on the outboard and the controller is installed on the boat in a waterproof location. The controller can be connected to the engine rpm sensor, boat speed sensor, and outboard gear shifter. The controller can take the inputs from engine rpm, boat speed sensor, and gear shifter and computes the right pitch angle for the propeller. The controller activates the actuator to move the control rod by a precise amount. The push-pull rod moves the plunger bearing mount. The plunger bearing mount moves the plunger. The plunger rotates the propeller base at a precise angle while keeping its position locked all the time.

In one implementation, the controller can compute and adjust the positive pitch of the propeller as well as the negative pitch. In case the user sets the electronic gear shifter forward, the controller sets the pitch of the propeller to a positive valve and hence the boat moves forward. But if the user sets the electronic gear shifter to reverse, the controller sets the pitch of the propeller to a negative valve and hence the boat can brake very effectively because of reverse thrust and can also move backward. The disclosed device allows for thrust reversal, without changing the gear to reverse on the outboard itself. The outboard can be built without a reverse gear mechanism and still allow the boat to be moved backward and brake more effectively using the disclosed device.

The controller can include a sophisticated algorithm to determine the optimum blade angle for better fuel efficiency, acceleration, and thrust reversal/braking. It takes the controller-less than 2 milliseconds to compute a solution for optimum blade angle and instruct the servo to change the blade angle and keep the blade angle locked until further instruction.

In one implementation, the variable pitch propeller and the controller can also have a built-in collision avoidance algorithm that takes inputs from proximity sensors on the boat hull in strategic locations and sets the pitch to 0 degrees for zero net thrusts in the event of one of the sensors being triggered to reduce damage to the hull.

In one implementation, the controller can also have a GPS module and inertial navigation module, both modules work together and allows autonomous navigation of the boat, preprogrammed, acceleration regime for the boat, preprogrammed cruise speed, and auto parking.

While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above-described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention as claimed. 

What is claimed is:
 1. A device for an outboard motor, the device comprises: a variable pitch propeller having a front side and a rear side, the variable pitch propeller configured to mount to a shaft of the outboard motor at the front side; a pitch control assembly operably coupled to the rear side of the variable pitch propeller, the pitch control assembly configured to change a pitch of the variable pitch propeller; and a mounting member configured to mount the pitch control assembly to a body of the outboard motor.
 2. The device according to claim 1, wherein the mounting member is configured to mount the pitch control assembly to a top fin hard point of the outboard motor.
 3. The device according to claim 1, wherein the pitch control assembly comprises: an actuator frame; a servo motor encased within the actuator frame; and a link member operably coupled to the servo motor and configured to translate rotary motion of the servo motor into linear motion of a push pull rod.
 4. The device according to claim 3, wherein the variable pitch propeller comprises: a propeller hub, the propeller hub has a plurality of first holes; a plurality of propeller bases mounted to the plurality of first holes, the plurality of propeller bases encased within the propeller hub; and and a plurality of propeller blades mounted to the plurality of propeller bases, wherein each of the plurality of propeller bases is configured to translate the linear motion of the push pull rod to rotary motion of the respective propeller blade of the plurality of propeller blades.
 5. The device according to claim 3, wherein the link member is an Acme screw.
 6. The device according to claim 4, wherein the propeller hub is of a hollow cylindrical profile.
 7. The device according to claim 4, wherein the pitch control assembly further comprises: a plunger operably coupled to the push pull road and encased within the propeller hub, the plunger is configured to linearly move within the propeller hub, wherein the plurality of propeller bases are coupled to the plunger through a cam crank mechanism.
 8. An outboard motor comprising: a device, the device comprises: a variable pitch propeller having a front side and a rear side, the variable pitch propeller configured to mount to a shaft of the outboard motor at the front side; a pitch control assembly operably coupled to the rear side of the variable pitch propeller, the pitch control assembly configured to change a pitch of the variable pitch propeller; and a mounting member configured to mount the pitch control assembly to a body of the outboard motor.
 9. The outboard motor according to claim 8, wherein the mounting member is configured to mount the pitch control assembly to a top fin hard point of the outboard motor.
 10. The outboard motor according to claim 8, wherein the pitch control assembly comprises: an actuator frame; a servo motor encased within the actuator frame; and a link member operably coupled to the servo motor and configured to translate rotary motion of the servo motor into linear motion of a push pull rod.
 11. The outboard motor according to claim 10, wherein the variable pitch propeller comprises: a propeller hub, the propeller hub has a plurality of first holes; a plurality of propeller bases mounted to the plurality of first holes, the plurality of propeller bases encased within the propeller hub; and and a plurality of propeller blades mounted to the plurality of propeller bases, wherein each of the plurality of propeller bases is configured to translate the linear motion of the push pull rod to rotary motion of the respective propeller blade of the plurality of propeller blades.
 12. The outboard motor according to claim 11, wherein the link member is an Acme screw, and the propeller hub is of a hollow cylindrical profile.
 13. The outboard motor according to claim 11, wherein the pitch control assembly further comprises: a plunger operably coupled to the push pull road and encased within the propeller hub, the plunger is configured to linearly move within the propeller hub, wherein the plurality of propeller bases are coupled to the plunger through a cam crank mechanism.
 14. A method for controlling a pitch in an outboard motor, the method comprising: providing a device for the outboard motor, the device comprises: a variable pitch propeller having a front side and a rear side, the variable pitch propeller configured to mount to a shaft of the outboard motor at the front side, a pitch control assembly operably coupled to the rear side of the variable pitch propeller, the pitch control assembly configured to change a pitch of the variable pitch propeller, and a mounting member configured to mount the pitch control assembly to a body of the outboard motor.
 15. The method according to claim 14, wherein the mounting member is configured to mount the pitch control assembly to a top fin hard point of the outboard motor.
 16. The method according to claim 14, wherein the pitch control assembly comprises: an actuator frame; a servo motor encased within the actuator frame; and a link member operably coupled to the servo motor and configured to translate rotary motion of the servo motor into linear motion of a push pull rod.
 17. The method according to claim 16, wherein the variable pitch propeller comprises: a propeller hub, the propeller hub has a plurality of first holes; a plurality of propeller bases mounted to the plurality of first holes, the plurality of propeller bases encased within the propeller hub; and and a plurality of propeller blades mounted to the plurality of propeller bases, wherein each of the plurality of propeller bases is configured to translate the linear motion of the push pull rod to rotary motion of the respective propeller blade of the plurality of propeller blades.
 18. The method according to claim 16, wherein the link member is an Acme screw.
 19. The method according to claim 17, wherein the propeller hub is of a hollow cylindrical profile.
 20. The method according to claim 17, wherein the pitch control assembly further comprises: a plunger operably coupled to the push pull road and encased within the propeller hub, the plunger is configured to linearly move within the propeller hub, wherein the plurality of propeller bases are coupled to the plunger through a cam crank mechanism. 